Washington, Aug 15 (IANS): A 17-year-old teenager in the US city of Philadelphia was in contact with a global terrorist group affiliated with the Al Qaeda and had access to a "significant" number of guns and was building bombs to conduct an attack, according to the FBI.

Addressing a press conference on Monday, FBI Special Agent in Charge Jacqueline Maguire said the teen, who was arrested on August 11 and has not been named,"conducted general research" into potential targets that weren't confined to one location, and they were not just in Philadelphia, Fox News reported.

"Most concerning was the evidence to his access to firearms and purchased items and materials commonly (used) for constructing improvised explosive devices," Maguire said.

"Among the items he purchased were tactical equipment, wiring, chemicals and devices often used as the detonators."

These purchases were made within the last few weeks, which quickly escalated this case "in both threat and priority", she said.

Investigators monitored the suspect's activity after learning he was in contact with the terrorist group Katibat al Tawhid wal Jihad (KTJ), an Al Qaeda-affiliated group that primarily operates in Syria's Idlib province.

He allegedly sent and received media to and from the KTJ on Instagram in March and April that contained terrorist propaganda and guidance on committing to criminal acts, including how to construct a bomb, according to the FBI.

He "appeared to be taking steps to travel overseas for the purpose of joining or supporting terrorist activity", Fox News quoted Maguire as saying.

In a statement, Philadelphia District Attorney Larry Krasner said that the suspect wasn't named because of his age and is currently facing state charges, although both of those will likely change.

The charges are weapons of mass destruction, criminal conspiracy, arson, causing or risking catastrophe, attempt to commit criminal mischief, possession of an instrument of crime and reckless endangerment of another person, Krasner added.